Durability investigation and performance study of hydrothermal synthesized platinum-multi walled carbon nanotube nanocomposite catalyst for proton exchange membrane fuel cell (original) (raw)
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Pt/MWCNTs nanocomposite: a durable electrocatalyst for proton exchange membrane fuel cells
2021
Extensive research and development efforts are being under taken in recent year in the field of PEM fuel cell (PEMFC) systems to make them commercially viable. In proton exchange membrane fuel cells, stability and durability are important objects for commercialization. It is well-known that catalyst degradation and carbon-support corrosion are the main factors reducing stability, and using Pt nanocatalyst on carbon nanotube supports instead of Pt/C increase stability and durability after long-term aging. In this work, a hydrothermal method was employed to prepare Pt nanoparticles dispersed highly on multiwalled carbon nanotubes with 19.4 wt. % Pt. Membrane electrode assembles (MEAs) from tow catalyst fabricated with thin film method. In fuel cell test station, the polarization, ac impedance and cyclic voltammetry experiment of MEAs and also ADT test was done. The Pt/C catalyst showed no activity in fuel cell testing after 2000 potential cycles due to severe carbon corrosion, Pt diss...
2011
A hydrothermal method for preparation of size-controlled Pt nanoparticles dispersed highly on multiwalled carbon nanotubes (Pt/MWCNTs) has been studied to optimize the effective parameters (temperature, time, pH and stirring rate) using Taguchi method. The synthesized Pt/MWCNTs nanocomposite samples were characterized through X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray fluorescence (XRF) analyses to identify mean Pt nanoparticles size and Pt content. The analysis of the primary experimental data and demonstration of the main effect trend of each parameter showed that a reaction temperature of about 140 C, a reaction period of 5 h, a slightly basic reaction pH (w9) and a stirring rate of 500 rpm are the optimum process conditions which give a low mean Pt nanoparticles size (2.8 nm) and a high Pt content (19.4 wt.%) simultaneously. Cyclic voltammetry (CV) analysis showed that under optimum conditions the synthesized sample gives a specific surface area of 99 m 2 g À1. Obtaining the polarization curves for the two fabricated membrane electrode assemblies (MEAs) using the optimized catalyst and a commercial Pt/C catalyst (10 wt.%, Aldrich) with Pt loading of 0.4 mg cm À2 demonstrated that the catalyst prepared under optimum conditions shows a considerably better performance.
Electrochimica Acta, 2010
Micelle-encapsulated multi-walled carbon nanotubes (MWCNTs) with sodium dodecyl sulfate (SDS) were used as catalyst support to deposit platinum nanoparticles. High resolution transmission electron microscopy (HRTEM) images reveal the crystalline nature of Pt nanoparticles with a diameter of ∼4 nm on the surface of MWCNTs. A single proton exchange membrane fuel cell (PEMFC) with total catalyst loading of 0.2 mg Pt cm −2 (anode 0.1 and cathode 0.1 mg Pt cm −2 , respectively) has been evaluated at 80 • C with H 2 and O 2 gases using Nafion-212 electrolyte. Pt/MWCNTs synthesized by using modified SDS-MWCNTs with high temperature treatment (250 • C) showed a peak power density of 950 mW cm −2 . Accelerated durability evaluation was carried out by conducting 1500 potential cycles between 0.1 and 1.2 V with 50 mV s −1 scan rate, H 2 /N 2 at 80 • C. The membrane electrode assembly (MEA) with Pt/MWCNTs showed superior performance stability with a power density degradation of only ∼30% compared to commercial Pt/C (70%) after potential cycles.
Pt/SWNT−Pt/C Nanocomposite Electrocatalysts for Proton-Exchange Membrane Fuel Cells
The Journal of Physical Chemistry C, 2007
Single-walled carbon nanotubes (SWNT) have been synthesized by pyrolysis of methane over Mm (Mischmetal)-based AB 3 alloy hydride catalyst. Purification of as-grown SWNT was carried out by air oxidation followed by acid treatment. The as-grown and purified SWNT have been characterized by XRD, SEM, TEM, HRTEM, TGA, IR, and Raman spectroscopy studies. Well-dispersed Pt catalysts on SWNT catalyst support for polymer electrolyte membrane fuel cells (PEMFC) have been prepared by a simple chemical reduction method using prefunctionalized SWNT. The anode and cathode electrodes for PEMFC have been fabricated using Pt-supported SWNT and commercial Pt/C electrocatalysts with different compositions of Pt/SWNT and Pt/C. The dependence of the fuel cell performance on the dispersion and accessibility of SWNT support and Pt electrocatalysts in the electrocatalyst mixture for the oxygen reduction reaction in PEMFC has been discussed. These results open up a way to use Pt/SWNT + Pt/C nanocomposites as electrocatalysts in PEMFC.
Langmuir, 2002
We have investigated properties of electrochemically deposited platinum black by atomic force and scanning electron microscopy. Platinum black was deposited on evaporated platinum electrodes. Deposition time and cure temperature was found to influence the quality and morphology of the platinum black layer. Morphological inclusions were readily observed in films deposited for duration of less than 60 seconds at a bias of 1.5 V against a platinum counter electrode. Shorting of the microfabricated electrodes due to lateral outgrowth of high surface area platinum black was observed when current densities on the order of 100 mA cm −2 were employed. We further show that reproducibility of highly adherent platinized electrodes is achieved. C 2000 Kluwer Academic Publishers
Heat-treated multi-walled carbon nanotubes as durable supports for PEM fuel cell catalysts
Electrochimica Acta
To improve their electrochemical stability as catalyst supports for proton exchange membrane (PEM) fuel cells, carbon nanotubes (CNTs) are heat treated in an ammonia atmosphere. High-resolution transmission electron microscopy, nitrogen adsorption, Raman spectroscopy, and X-ray photoelectron spectroscopy are employed to study the temperature effect on the structure of the heat-treated CNTs (H-CNTs), and a thorough investigation of their resistance to electrochemical oxidation is also measured by an electrochemical technique. The amount of surface oxides on the CNTs is visibly high in comparison to the H-CNTs after 48 h of oxidation, indicating that the H-CNTs have a higher resistance to electrochemical oxidation. Pt nanoparticles supported on both CNTs and H-CNTs are fabricated through a polyol process in an ethylene glycol solution. The improvement of the dispersion of Pt nanoparticles on nanotubes from the heat treatment is demonstrated, and the results show that the Pt nanoparticles deposited on the H-CNTs heated at 1000 • C are electrochemically accessible. Therefore, they can be used as a durable support for Pt catalysts in fuel cells.
Materials for Renewable and Sustainable Energy, 2016
Multiwalled carbon nanotubes platinum nanocomposite has been prepared via chemical route by reduction of Pt salt on MWCNTs in ethylene glycol solution while refluxing in Argon atmosphere. The effect of different pH media during the reduction process on their physical and electrochemical properties, as well as on their performance in unit PEM fuel cell has been studied and further compared with the reaction carried out while refluxing in air as already demonstrated by the authors. The I-V performance of unit PEM fuel cell shows a peak Power density of 156 mW cm-2 with catalyst prepared in alkaline medium, an increase of [ 110 % as compared to 72 mW cm-2 obtained while employing catalyst prepared in acidic medium and tested under similar conditions. This is attributed not only to the small particle size of reduced Pt NPs, but also to its uniform distribution when reduction is carried out in alkaline medium. This has been further explained by detail reaction mechanism under alkaline conditions.
Journal of Porous Materials, 2015
Commercially available multiwalled carbon nanotubes (MWCNTs) were functionalized using a mixture of HNO 3 and H 2 SO 4 in refluxing condition under three different reaction times (1, 3, and 5 h). The Pt loaded on functionalized MWCNTs (f-MWCNTs) (Pt/1f, 3f & 5f-MWCNTs) were prepared by reducing chloroplatinic acid and for comparison Pt loaded on pristine MWCNTs (Pt/MWCNTs) was also prepared. The size of Pt nanoparticles was determined using X-ray diffraction method. The uniform dispersion of the Pt catalyst on CNTs was confirmed by HRSEM and HRTEM. Surface area and pore size were calculated by Brunauer Emmett Teller analysis method. Five membrane electrode assembly sets were prepared (Pt/MWCNTs, Pt/1f, 3f, 5f-MWCNTs and commercial Pt/C) and tested in the fuel cell assembly. The first four were prepared using SPEEK membrane as electrolyte with the synthesized Pt/f-MWCNTs catalysts and the fifth one was prepared using commercial Nafion-117 electrolyte and Pt/C electrode for comparison.